A teenager was arrested on Sunday after a child fell "from height" at London's Tate Modern gallery, police said.Initial reports said the contemporary art museum on the bank of the River Thames was evacuated, but these could not immediately be confirmed."Officers are in the vicinity of the Tate Modern following an incident this afternoon," a brief statement from the Metropolitan Police said."A child fell from height and is being taken to hospital by London's Air Ambulance. We await an update on his condition. "A teenager has been arrested in connection with the incident."The Tate Modern is Britain's top visitor attraction, with 5.87 million visits in 2018, according to the Association of Leading Visitor Attractions.